Abstract: A method of adjusting the power of a vacuum cleaner fan comprising a vacuum switch having a single switching point includes using the vacuum switch to create a signal indicative of a vacuum pressure created by the vacuum cleaner fan. The method also includes filtering the signal to obtain a resulting signal, the resulting signal being a measure of the vacuum pressure. The method further includes using the resulting signal as a controlled variable for adjusting the fan power with an electronic control system.

Abstract: A hand lever includes a sleeve-shaped member having an inwardly protruding projection, a fastening element having a stop interacting with the projection, wherein the fastening element is mounted in the sleeve-shaped member so as to be longitudinally slidable to a limited extent, and coupling elements for axially coupling the hand lever and fastening element so as to be nonrotatable relative to each other. A spring is mounted in the sleeve-shaped member for an axially engageable and disengageable coupling of the hand lever and the fastening element. The fastening element has an integrally formed extension part extending past the projection of the sleeve-shaped member into the sleeve-shaped member. A second support is provided for the spring and the stop of the fastening element or the extension part. At least one of the sleeve-shaped member and the extension part is of a resilient material.

Abstract: A hand lever includes a sleeve-shaped member having an inwardly protruding projection, a fastening element having a stop interacting with the projection, wherein the fastening element is mounted in the sleeve-shaped member so as to be longitudinally slidable to a limited extent, and coupling elements for axially coupling the hand lever and fastening element so as to be nonrotatable relative to the each other. A spring is mounted in the sleeve-shaped member for an axially engageable and disengageable coupling of the hand lever and the fastening element. The fastening element has an integrally formed extension part extending past the projection of the sleeve-shaped member into the sleeve-shaped member. A second support is provided for the spring and the stop of the fastening element or the extension part. At least one of the sleeve-shaped member and the extension part is of a resilient material.